This invention relates to hydraulic pumping systems for pumping hydrocarbon fluids, and, more particularly, to control of the flows through the cyclone separator and of the level of the fluid in the horizontal suction vessel.
Hydraulically actuated downhole pumps have been used rather than beam-pumping units in many locations. Hydraulic pumping units are especially attractive in deeper and higher producing wells, but the downhole pumps for such systems have required frequent maintenance.
A hydraulic pumping system uses an above-ground pump (typically, a triplex pump) to supply pressurized fluid, some of which is used to actuate the downhole, hydraulically actuated pump. The downhole pump generally returns at least some of the power fluid, together with produced well fluids. A portion of the return fluid is then conditioned by a cyclone separator for use as power fluid. In the past, there has apparently been no automatic throttling on the underflow of the cyclone separator (however, valves, which close automatically when the power is off, have been used) and the level in the suction vessel has been controlled by sensing the level and, in effect, dumping fluid to the flowline when the level reaches some predetermined point.
Hydraulic pumping systems are described in, for example, U.S. Pat. Nos. 2,046,769, 2,119,737, and 2,593,729, issued to Coberly; and U.S. Pat. Nos. 3,709,292 and 3,782,463, issued to Palmour.